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- Based on the timeline, which of the following embryologic processes is most likely occurring in the embryo at this stage?
Based on the timeline, which of the following embryologic processes is most likely occurring in the embryo at this stage?
Dr. Shoaib Ahmad Baig
February 13, 2025
🔍 Morning Quiz ☕️
A 24-year-old woman with regular 28-day menstrual cycles presents to the clinic after missing her period. Her last menstrual period began 7 weeks ago, and she had unprotected intercourse once 5 weeks ago. She has no significant medical history. A urine pregnancy test confirms she is pregnant.
Based on the timeline, which of the following embryologic processes is most likely occurring in the embryo at this stage?
A. Blastocyst implantation
B. Gastrulation
C. Intestinal fixation to the abdominal wall
D. Neural crest migration
E. Primitive alveoli formation
Correct Answer 🎯: D. Neural crest migration
⚙️
🧠 Fertilization (Day 0) → Formation of Zygote
⬇
⚙ Morula Formation (Day 3-4) → Early Cell Division
⬇
⚙ Blastocyst Formation (Day 5-6) → Ready for Implantation
⬇
🧠 Blastocyst Implants in Uterus (Day 6-10) → hCG Production Begins
⬇
⚙ Gastrulation (Week 3) → 3 Germ Layers Formed (Ectoderm, Mesoderm, Endoderm)
⬇
⚙ Neural Crest Migration (Week 5) → Key Organ & Tissue Development Begins ✅
Peripheral ganglia 🧠 → Sensory & Autonomic Nervous System
Schwann cells ⚙ → Myelination of Peripheral Nerves
Adrenal medulla 🔥 → Catecholamine Production
Craniofacial structures 🏗 → Skull, Face, Pharyngeal Arches
Aorticopulmonary septum ❤️ → Heart Outflow Tract Formation
⚖️ Explanation of Other Differentials
Differential ⚖️ | Time Frame ⚙️ | Why Incorrect? 🔴 |
|---|---|---|
Blastocyst Implantation | Day 6-10 | Already completed by 5 weeks post-conception |
Gastrulation | Week 3 | Completed earlier, now forming specialized tissues |
Intestinal Fixation | Week 10+ | Occurs later, after midgut returns to abdomen |
Primitive Alveoli Formation | Week 16+ | Happens in the Canalicular stage, not at week 5 |
⌛️ Practice Time!
UWorld Questions with IDs-
108284, 955, 1490, 507
Stay Hungry, Stay Curious!
Your Brother in this Struggle
Dr. Shoaib Ahmad
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